The purpose of this contract effort is to continue a longitudinal follow-up Of metabolic and psychological function in 227 offspring of diabetic mothers for five more years. These children were born during the period 1978-1983, and they are now 8-13 years old. The metabolic status of the mothers of these children was documented in detail during their second and third trimesters, and amniotic fluid insulin levels were assayed as well. The study is designed to test the hypothesis that perturbations in fetal substrate supply affect the intrauterine development of terminally differentiated, poorly replicating cell such as adipocytes, beta-cells of the endocrine pancreas and neurons. The study group consists of 118 offspring of mothers with gestational diabetes mellitus, 109 offspring of mothers with insulin-dependent pregestational diabetes mellitus and 45 offspring of normal non-diabetic mothers who were screened for gestational diabetes mellitus and whose peak level of plasma glucose was less than 130 mg/dL.